1. Technical Field
The present invention relates to a deceleration sensor switch, and, in particular relates to a vehicle deceleration sensor switch for use in a vehicle occupant restraint system.
2. Background Art
Vehicle deceleration sensor switches for use in a vehicle occupant restraint system, such as an inflatable air bag system, are known. Typically, a vehicle deceleration sensor switch has electrical contacts which close in response to the vehicle experiencing deceleration of at least a predetermined magnitude for a time interval, such as occurs in a vehicle collision. Upon closing of the contacts, a firing circuit is completed which triggers an inflator to provide a flow of inflation fluid. The inflation fluid is directed into an inflatable air bag to inflate the air bag. The inflated air bag absorbs energy resulting from the movement of the vehicle occupant against the air bag and prevents the vehicle occupant from violently striking parts of the vehicle during the vehicle collision.
The contacts of the deceleration sensing switch must remain closed for a sufficient time to ensure reliable completion of the firing circuit and thereby reliable inflation of the air bag. Some known deceleration sensor switches may use frictional resistance to prolong contact closure time, such as disclosed in U.S. Pat. Nos. 3,753,475 and 3,571,539.